AssocRacer, make sure you have ventilated the body properly before you do anything else. A tight fighting, unventilated body on a 4x4 buggy will burn up any ESC. I'm running a VTX10R 6.5 in my Durango DEX410 with no fan. I should probably have a fan. Higher throttle and brake frequencies will build heat in the ESC too. Check where those are set.